Amid the swift process of urbanization, mental health challenges among city inhabitants have become increasingly prominent. Urban green spaces, owing to their potential mental health benefi ts, have attracted growing interest in urban planning and public health research. Although numerous studies have investigated the relationship between green space and mental health, the underlying mechanisms remain poorly understood. Based on a systematic review of empirical studies from the past fi fteen years retrieved from CNKI and Web of Science, this study employs bibliometric analysis to examine research distribution, target populations, and methodological features. It further explores the pathways through which green space infl uences mental health. The fi ndings reveal substantial growth in research volume and a shift in focus from macro-level indicators, such as the quantity and area of green space, to more granular assessments that emphasize quality and spatial confi guration. Green space impacts mental health both directly—through its type, scale, and confi guration—and indirectly, via mediating pathways such as perceived environmental quality, physical activity, and social connectivity. However, the eff ects vary signifi cantly depending on individual characteristics, socioeconomic status, and the level of built environment development. Current research faces limitations, including a lack of diverse measurement approaches, insuffi cient causal explanations, and weak theoretical integration. Future studies should adopt longitudinal designs, deepen analyses of mediation and moderation mechanisms, and strengthen theoretical frameworks to build a more comprehensive “green space–mental health” model, thereby informing health-oriented urban green space planning and policy development.